Processing of sulfur-vulcanizable materials, and related compositions



2,625,528 AND W. T. COOPER -l -VULCANIZABLE MATERIALS, RELATED COMPOSITIONS Filed April 6, 195] Jan. 1 3, 1953 PROCESSING 0F SULFUR Patented Jan. 13, 1953 PROCESSING OF SULFUR-VULCANIZABLE MATERIALS, AND RELATED COMPOSITIONS William T. Cooper, Phillips, Tex., assgnor to Phillips Petroleum Company, a corporation of Delaware Application April 6, 1951, Serial No. 219,708

17 claims. l

This invention relates to plasticizers and eX- tenders and to their utilization in processing sulr fur-vulcanizable organic plastic substances containing unsaturated carbon-to-carbon bonds, and

`2 that they do not possess sufcient tack. A plasticizer which gives a product of improved tack as well as other good physical properties is highly desirable.

to compositions associated with such processing. 5 I have now discovered novel softeners and eX- In one embodiment, this invention relates to a tenders, which by their incorporation with rubmethod for plasticizing natural and synthetic ber stocks, are good rubber plasticizers and tackirubbers. In another embodiment this invention ers and also impart other desirable properties relates to a method for extending natural and to the rubber. These materials are applicable in synthetic rubbers. In still another embodiment l0 compounding natural and synthetic rubbers and this invention relates to new compositions comreclaimedrubber, and they can be used alone as prising natural rubber and synthetic rubber each softeners and tackiers in a compounding recipe incorporated with a total residual by-product 0r as mixtures with each other, or in conjuncof catalytic dehydrogenation of a C4 hydrocartion with other softeners. They are effective not bon to produce a less saturated C4 hydrocarbon, 15 only as extenders, plasticizers and tackiiiers-but from which all components boiling below 300 the rubber in which they are used shows par- F have been removed, y, I ticularlygood flex life and tensile strength.

Rubber stocks are tough and nonplastic and An object of this invention is to provide new must be softened or rendered in'a plastic conand novel plasticizers and extenders for-,utilizafdition t0 facilitate processing with ingredients 20 tion with natural and synthetic rubbers. An- 'to be incorporated therewith. Examples of such other object is to provide a method for plasticizingredients are reinforcing pigments such as ing and extending sulfur vulcanizable organic carbon black, fillers such as zinc oxide, various plastic substances containing unsaturated `caraccelerators, sulfur, and the like. These combOn-tO-carbon bonds. Another object is to propounding materials are among those which in vide new COmpOSitOnS each Comprising a sulfur various combinations impart to the vulcanizate Vulcanizable organic plastic substance containimprovements in such properties as abrasion reing unsaturated carbon-to-carbon bonds, incorsistance, flex life, hysteresis, resistance to tear, Dore-ted With that DOI'OH 0f a total residual bytensile strength, elongation, modulus, etc. product of catalytic dehydrogenation of a C4 Mixing of tough rubber stocks with compoundso hydrocarbon to producea less Saturated C4 hying ingredients is generally eiected by means of drocarbon, from which all components boiling mastication at a controlled temperature in. the below 300 F. have been removed. Another obrange of 50-35c F. Mastication involves meject is t0 provide selected vulcanizates as new chanically kneading the rubber material, either Compositions. Other Objects Will be apparent t0 by passing it through an open mill, i. e., passing one skilled in the art from the accompanyin it between rollers running at different speeds discussion and disclosure. v

whereby it is subjected to compression followed The term sulfur vulcanizable organic plastic by a shearing action, or by placing it in an ensubstance containing unsaturated carbon-toelesed mixer of the Banbury type Where mueh Ycarbon bonds is meant herein to be generic to the same eiect is produced. The open mill and 40 natural rubber, Synthetic rubber and reclaimed the Banbury type mixer comprise standard equiprubber. .A Vment in compounding rubber. Various known Onewell known method for the manufacture 'agents which are used to accelerate milling by of 1,3.-butadiene involves a vseries of steps vin virtue of their affinity for the rubber or rubberwhich n-butane is dehydrogenatedin the preslike material are referred to hereinafter as plasence of a catalyst-to produce predominantly 1- ticizers or softeners, i. e., as applied to synbutene and 2-butene, followed by a pluralityof thetic, natural, and reclaimed rubber. fractionation steps for the recovery of the butene Various types of materials have been employed products formed, catalytic dehydrogenation of as softeners or plasticizers for both natural and the recoveredbutenes to .produce 1,3-butadiene, synthetic rubbers and it is known that variations 4and nally a plurality of fractionation steps for in properties of rubber products can be produced the .recovery of the LB-butadiene so produced. lthrough the use of different plasticizing agents. `During each. of. these .catalytic dehydrogenation A good plasticizer, in addition to softening a rubsteps a residual by-product 011 is. formed, and ber stock, must give a nished product with other comprises a mixture of heavier hydrocarbons desirable properties. Some materials which excontainingfrom 5 carbon atomsup to as high as ert the desired plasticizing action often have dele- 20 carbon atoms per molecule and higher. Preterious effects on other properties to the extent -cise molecular structures of the heavier 0i1 comthat the nnished product, i. e., the vulcanizate, ponents are not known. I have discovered that is of little value for many purposes. One of the the total by-product oil thus formed in either of disadvantages of some synthetic elastomers is the catalytic dehydrogenation steps described from which all components boiling below 300 F. have been removed, is an excellent plasticizerextender for natural rubber, synthetic rubber or rubber substitutes, and reclaimed rubber, and that it imparts excellent characteristics to vulcanizates formed from compoundedrubbers containing it. I have provided 'in accordance with my invention a method employing such a residual by-product oil as that described, fo'rplas'ticizing and extending sulfur vulcanizableorganic plastic substances containing unsaturated carbon-tocarbon bonds, and for compositions comprising such organic plastic substances incorporated with such a residual oil by-product, including the compounded rubber containing the residual oil, and vvulcanizates formed from such va compounded rubber.

In order to describe in some detail the origin of the novel plasticizer-extenders cf my invention, reference is made to the attached drawing which is a diagrammatic `flow sheet illustrative of the operation of a multi-step system for the manufacture of LEI-butadiene utilizing 'n-buta'ne Vasa rstarting material. It is t'o be understood'that KMthe drawing isdia'g'rammatic 'and can be altered in 'many respects by those skilled inthe artand still depict the manner in which the vplastici'z'erextender materials of my invention are formed.

'With reference tothe iigure, 'rl-buta'rle from line I is 'preheated in preheat chamber II vto a tem-- 'perature generally within the range f 'from about 1000'to 1200'F. more often'to about 1100 F., and then passed from zone II through vline I2 into n-butane dehydrogenation chamber I3 containingr :a "catalyst `active 'in -promoting dehydro- 'genation of n-butane to form l-butene and "2- butene. Such a catalyst is freonentlv one consistmer essentially of alumina and chromia, prei- 'erablv one containing chromia in a minor proportion, as for example one containing from 15-40 per cent chromia and 60-85 ner cent alumina. One such catalyst used commercially ls'a 20 `ner cent chromia-BO per cent alumina catalyst. n-Butane. feed is passed through chamber I3 at a snace velocity within the limits nf 300 and 1000. more often within the limits of 500 and "750 standard gas volumes per catalvst volume ner hour at the 'prevailing temperature. aifhmwh it is Varied dependent unrm the antivi-,v 'nf the data IVS. 'Total efuent from n-hutane dnhvrlrngpnntion 7nr1e i3 is passed thrm'iah line III intn'tntq] emugni; fraotionatinn svstem IG nnmnr-cng frac- 1310112150". eolii'hmeht. i. e. distillation and solvent; .evtrqption mp3-ng qnnovq'nrs storage ternir.: and the'lilre. not snericallv illustrated, 'which may be utili'zed 'In the. separat-inn and rnnnverv n1 verimishnmnonents in tbn, 'Irma i2 nflwnntjra'rtfu- 'gern '(51. (la. and fle hvdvnnarhonsbrn 'withdrawn from fractionation gvd-.nm is through line l1. Bui-,arlinne fmmnr in relativelv small 'amounts in 'zrm'e 53, is separated in anne IG and withdrawn hhrnunfh lino. M Aviv 'ra-mitaines present; in emu.. entsfr'rom chamber I3 is'senarated in vorne I R and witbdrawn'through line 2I for recvcleto line I 0.

"'Butenes. predominantly 1`butene and' 2-butene,

'are discharged from fractionation system' through line I9.

ranges but whose structure is not known with sparticularity. The V following tabulation presents a typical analysis of a by-product oil formed in chamber I3 and withdrawn from the system through line 22 Liq. vol. A. Non-aromatic hydrocarbons: per Cent Css 0.6 4-vinyl cyclohexene-l (butadiene dimer) 2.8 5-methyl 1,3-cyclohexadiene 2.1 IZ-methyl 1,3-cyc1ohexadiene v2.1 'Z3-dimethyl 1,3-cyclohexadiene .1.'0 Unidentified component (cut No. 7) 1.8

B. Aromatic hydrocarbons:

1. Benzene and derivatives- Benzene A 0.7 Toluene 4.0 Ethyl benzene 9.6 uP-xylene '6;8 'M-Xylene 2.7 O-'Xylene 17.7 Isopropyl benzene 4.0 1,2,3- and 1.2.4-trimethy1 lbenzene's 0.9 fOctyl benzene and similar aromatics llLO 1,3-dimethyl l-ethenylV benzene 11.9

2. :Naphthalene derivatives and .miscellaneousv1\Tap`l'1tl'ialene e 11.8 1,4-diisobutyl naphthalene 2;5 Blue oil (B. pt. 445-490 F.) possibly derivative of azulene 11.0 Green oil (B pt. 495-525 F.) possibly derivative of hexacene or heptacene 7.0 Yellow oil (possibly'terpenes) 0.5 Kettle'residue 15.0

The above analysis is presented on a Csi-free basis. It is understoodthat in some instances a very small amount of C4 hydrocarbons may be present in the material withdrawn through line 22 inasmuch as under some conditions the fractionation may not have been so precise as to separate completely the oil by-product from Cis.

Butenes in line I9 comprising l-butene and 2butene and containing in some instances a small proportion of sobutene, are admixed with steam, introduced into line I9 through line 23, and the resulting steam-butene admixture is passed into preheat chamber 24 and heated therein to a temperature generally within the limits of about 1100 and 1300 often at about 1150-1250 F'. Eluent steam-butenes from zone 24 is passed through line 26 into dehydrogenation zone 2 containing a catalyst active in promot ing dehydrogenation of .a butene to form 1,3- butadiene. Alternatively ste-am is preheated to 1200-11100o F. and introduced into line 26 from line 28 andthe butene steam from line I9 is heated in zone 24 to 900 to 1100 F.; and the resulting steam-butene mixture is passed at its existing temperature into zone 21. The catalyst, employed in zone 21 is generally one high in iron oxide content, as for example, a catalyst containing from Y0-95 per cent FezOs including a minor amount ofFeaOi, 3-20 per cen-t chromia and from 2 to 20 per cent KOH. A catalyst comprising about 93 per cent FezOs, 5 per cent CrzOs and 2 per cent KOH has been frequently used commercially. Butenes from line 26 are passed through dehydrogenation zone 21 at a hydrocarbon space velocity generally within the limits of 200 and 500 standard gas volumes of total butenes per catalyst Volume per hour. Steam is generally introduced into chamber 21 in a mol ratio to total hydrocarbon within 4the limits of about 8:1 to 15:1. Total eiuents from chamber 21 are passed through line 2S into fractionation and separation system 3i, comprising Various product recovery and separation means not individually illustrated such as fractionation equipment, i. e. distillation and solvent extraction means, separators, storage tanks, and the like. Light gases comprising hydrogen, C1, C2, and C3 hydrocarbons are passed from fractionation system 3l through line 32. Unreacted butenes are withdrawn from fractionation system 3| through line 33 for recycle if desired. 1,3-but-adiene product, of specification grade, is withdrawn from Zone 3l through line 34. A total by-product oil, formed during the dehydrogenation in zone 21, is withdrawn from zone 3l through line 36. Oil Awithdrawn through line 3B comprises total residual by-product, i. e., heavier than C4s, of the catalytic dehydrogenation in zone 21 and comprises hydrocarbons containing at least 5 carbon atoms in a molecule and at least as high as 20 carbon atoms in the molecule, the molecular structure oi some of the components thereof having not as yet been established with certainty. The following tabulation presen-ts a typical analysis of a total by-product oil formed in chamber 21 yand withdrawn from the system through line 35:

Olefins Per cent Pentene-l 4.7 2-methyl-1-butene 15.5 2-methyl-2-butene 5.1 Methyl pentenes 2.1 Methyl hexenes 2.8 Dimethyl pentenes 2.8 Dimethyl hexenes 2.1

Diolefns 1,4-pentadiene 1.7 2methyll,3butadiene 9.5 3-methyl-1,2butadiene 6.3 1,2- and 1,3-pentadiene 3.6 2-methyl-L4-pentadiene .9 1,4- and 1,5-hexadienes .7 Methyl pentadienes 2.1 -methyl-1,3-cyclohexadiene 2.2 5,5- -and 1,5-dimethy1 hexadienes 5.2 /l-vinyl-l-cyclohexene (04H6 poly) 3.8

Aromatics Benzene 3.2

Toluene 9.4 Ethylbenzene 1.7 Xylenes 8.0 Styrene .5 1- and 2-phenyl-2-butenes .9 Blue oil (398-460 F.) 1.2 Green oil (4684185 F.) .8 Kettle residue 3.2

t is to be understood tha-t in some instances dependent upon the operation of fractionation system 3i, some C4 hydrocarbons may be present through line 3B.

'Ihe total residual oil in line 22, freed of all components boiling below 300 F. as measured at atmospheric pressure, is exemplary of one of the plasticizer-extenders of my invention. Separation of those lower boiling components from the total oil can be eiected by passing the oil from line 22 through line 31 in-to separation Zone 38, generally a distillation step, wherein all components boiling below 300 F. are separated, and are then withdrawn through line 39. Residual oil separated inzone 38, i. e., total oil from line 22 freed of al1 components boiling below 300 F. is withdrawn through line 4I as a plasticizer-extender of my invention.

The total residual oil in line 36, freed of all components boiling below 300 F. as measured at atmospheric pressure, is exemplary of another plasticizer-extender of my invention. Separation of those lower boiling components from the oil in line 36 can be eiected by passing the oil from line 36 through line 42 into separation zone 43, generally a distillation step wherein all components boiling below 300 F. are separated, and then Withdrawn through line 44. Residual oil withdrawn and separated in zone 43, i. e.,'total oil from line 36, freed of all components boiling below 300 F., is withdrawn through line 46 as a plasticizer-extender of my invention. y

Although I have stated that -a by-product oil such as that withdrawn through line 4| or line 48 can be utilized in the practice of my invention as a plasticiZer-extender, it is to be understood that mixtures of these oils can be utilized also. Accordingly, if desired, oil by-product from line 4l can be passed through line 43 into line 49 in admixture with oil by-product from line 46 passed into line 49 through line 41. The mixture con-taining the components from lines 4l and 46 in any desired proportion is then withdrawn from the system through line 49 as a plasticiZer-extender of my invention.

The proportions of the plasticiZer-extender materials employed with respect to the rubber stock in accordance with my invention vary, depending upon the type rubber being processed and the properties desired in the nished product, i. e., the plasticizer-rubber product preceding or subsequent to Vulcanization or both as desired. Generally the amount of plasticizer-extender` employed is within the limits of from 1 to 50 parts by weight per parts by weight of rubber stock. When plasticizing relatively high Mooney synthetic elastomers, for example those having raw Mooney values of 90 or above as for example as high as (ML-4), it is usually advantageous to employ relatively large quantities of plasticizer, for example from 15 to 50 parts by weight per 100 parts by weight of rubber. When plasticizing relatively low Mooney synthetic elastomers, i. e., those having a raw Mooney Value below 90, as from about 20 to 90, that amount is in the range of from about 1 to 25 parts, often from 2 to 10 parts. When referring herein to Mooney value, it is meant that Mooney viscosity as determined in accordance with the ASTM method, D927-49T.

I can incorporate the softeners of my invention with the material to be plasticized by any suit able method, such as (1) by adding the softener either directly or as a dispersion to a synthetic rubber latex and then coagulating the latex in accordance with latex masterbatch procedure, or (2) introducing the softener on the mill.

The following example serves to illustrate further a process for plasticizing natural and synthetic rubber and a new and novel plasticizer- The compounded stocks were milled and cured 30 minutes at 307 E., except as otherwise specified (in the,Vv following tabulation) and physical properties of each vulcanizate were determined. The following` evaluation data were obtained.

, ,Y Extrusion at 80 F 250 F.

200 F! Per- Abra- Per MS PHR 3 Flex5 Shore Plasticizcr sof- A Per- 'Een' AT F. ceptlife, hard- Sion cent 1% tener 300% Tem cem s1le,. res111- M ness loss, comp. at

modu- Sile, alom p. s. i. ence grams set 212 F. InJ Gms/ liai p. s. i. gav mm. mm. p' tion n-Butano dehydrogenation v gy-nodc ol 7 5 1, 420 3, 720 570 2, 300 70. 9 60. 1 23. 3 5S 2. 93 19. 0 47 37 9G. 5 nu anc e y rccena i011 Clay-prolduzctl-il 71; f 1 10 1, 180 3, 600 620 2, 020 75.0 60. 8 11. 0 56 3. 15 19. 5 41. 5 35. 5 98. 5

ircoso ara ux blend 1 10 1,140 3, 400 630 2, 110 71. 6 G0. 9 24. 4 55 4. 14 18. 6 42 30 97. 8

l 1,110 3, 57() 645 2, 310 72. 6 59. 9 40. 0 56 4.05 18. 4 42 38. 5 100 l0 1, 200 3, 550 660 2,200 73. 6 57. 8 3l. 7 59 3. 68 21. 0 48 36. 8 98. 5

O VEN anni) 24 HOURS AT 212 F.

n-Butancdehydrogenation .v n v lay-product oil 7 5 2, 800 3, 780 380 62. 5 64. 3 12. 9 65 3. 97 n-Butauc dehydrogenation Cby-prolduciil 7 f 1 10 2, 440 3, 970 430 63.2 L64. 8 9.8 64 4.01

`ircoso 2. -para ux P blejiid 38g 57. l G4. 2 l0. 5 6l ara ux v 10 4 5S. 5 (i5. l 15. 3 62 Asphalt No. c 1c 2, 030 3j 43o 61. 2 s2. 7 4. s 65 1 Equal partsCircosol ZXH with laraflux. Circosol 2KB: petroleum hydrocarbon softener containing high molecular Weight hydrocarbons; sp. gru-0.940; Saybolt'viscosityat 100 F., about 2000 seconds. "Paraflux: saturated polymerized hydrocarbon.

2 Asphalt softener.

3 Parts per 100 parts rubber.

4 45 minute cure.

5 Thousands of iiexures to failure. minute cure.

7 Total by-product oildescribed above from which all components boiling below 300 F. have been removed.

ingrdients employs, as iustated minces;

amples, are presented as being typical and vshould not be construed .to limit the invention. unduly.

' EXAMPLE I A total residual oil by-produot recovered from the effluent of catalytic butanedehydrogenation of the .type illustrated with reference to the drawing as eiected in dehydrogenation chamber kI3 and Withdrawn from the system. through lline 4I, i. e., total oil from line 22 from which. all components boiling below 300 F. as`measured at atmospheric pressurehave been removed was employed as a plasticizer. in the followingV tread recipe using a 41 F., 60 Mooney (ML-4), '7l/ 29 butadiene-styrene elastomer. Three commercial softeners were evaluated as controlsv for purpose of comparison. The n-butane dehydrogenation during which the butane dehydrogenation byproduct oil was formed .Was eiectedin the presence of a 20 per cent chromia-BO per cent alumina catalyst, at a space velocity of about 662 gaseous Volumesv n-butane per catalyst volume per hour, at a temperature of about 10401F. The follow'- ing compounding recipe was employed.

' f Parts by Weight Butadiene/styrene elastomer 100 Philblack O 1 50 Zinc oxide 3 Stearic acid 1 Flexamine 2 1 Sulfur 1.75 Santocure 3 1 Softener 4 Variable 1 High abrasion furnace black.

2 A physical mixture containing 65 per cent of a complex diarylamineketone reaction product and 3o per cent of N,N.-diplienyl-p-phenylenediamine.

f N-cyclohexyl-2-benzothiazolesulfenamide.

45 and 10 parts, respectively, for the butane dehydrogenation residue and 10 parts for each of the commercial softeners.

willmbe evident -to those skilled in the art, various modifications can be made or followed in the lightV of the foregoing disclosure and discussion Without departing from the spirit or scope ofthedisclosure or from the scope of the claims. -Iclaimz 1. A method for increasing the plasticity of a rubbery sulfur-vulcanizable organic plastic substance containing unsaturated carbon-to-carbon bonds, comprising incorporating with parts by weight of such an organic plastic substance from 1 to 50 parts by weight of a total residual oil by-product of catalytic dehydrogenation of a C4 hydrocarbon at a temperature Within the range of 1000-1300 F. to produce a less saturated C; hydrocarbon, said total oil being freed of all components boiling below 300 F. as measured at atmospheric pressure.

2. The method of claim 1 wherein said byproduct oil is formed during a dehydrogenation of n-butane in the presence of a catalyst comprising alumina in a major proportion and chromia in a minor proportion, at a temperature Within the range of from 1000 to 1200" F.

3. The method of claim 1 wherein said byproduct oil is formed during a dehydrogenation ofA a C4 moncolen to form a C4 diolen at a temperature within the limits of 1100 and 1300o F. in the presence of a catalyst comprising iron oxide, chromia and potassium hydroxide.

4. As a new composition a rubbery sulfur-vulcanizable organic plastic substance containing unsaturated carbon-to-carbon bonds incorporated With a total residual by-product oil formed during a catalytic dehydrogenation of a C4 hydrocarbon at a temperature within the range of 1000-1300 F. to produce a less saturated C4 hydrocarbon, freed of all components boiling below 300 F. as measured at atmospheric pressure.

5. The composition of claim 4 wherein said byproduct oil is formed during the catalytic dehydrogenation of n-butane to form butenes as chief dehydrogenation product.

6. The composition of claim 4 wherein said byproduct oil is formed during a catalytic dehydrogenation of a butene to form 1,3-butadiene as the chief dehydrogenation product.

7. A composition comprising 100 parts by weight of a sulfur-vulcanizable synthetic rubberlike material compounded with from 1 to 50 parts by weight of a plasticizer material comprising a total residual by-product oil formed during the catalytic dehydrogenation of a C4 hydrocarbon at a temperature within the range of 1000-1300 F. to produce a less saturated C4 hydrocarbon, freed of all components boiling at 300 F. as measured at atmospheric pressure.

8. The composition of claim 7 wherein said plasticizer material is formed during the catalytic dehydrogenation of normal butane at a temperature within the limits of 1000 and 1200 F. in the presence of a catalyst consisting essentially of alumina in a major proportion and chromia in a minor proportion.

9. The composition of claim '7 wherein said plasticizer material is a by-product oil formed during catalytic dehydrogenation of a butene in the presence of a catalyst consisting essentially of iron oxide in a major proportion and chromia and potassium hydroxide each in a minor proportion.

10. The product of vulcanization of 100 parts by weight of a rubbery sulfur-vulcanizable organic plastic substance containing saturated carbon-to-carbon bonds, which has been vulcanized with sulfur in the presence of from 1 tc 50 parts by weight of a total residual oil by-product of catalytic dehydrogenation of a C4 hydrocarbon at a temperature within the range of 1000a1300 F. to produce a less saturated C4 hydrocarbon, said total oil being freed of all components boiling below 300 C. as measured at atmospheric pressure.

11. The product of vulcanization of 100 parts by weight of a sulfur-vulcanizable synthetic rubber-like material which has been vulcanized with sulfur in the presence of from 1 to 50 parts by weight of a total residual oil by-product of catalytic dehydrogenation of a C4 hydrocarbon at a temperature within the range of 1000-1300 F. to produce a less saturated C4 hydrocarbon, said total oil being freed of all components boiling below 300 F. as measured at atmospheric pressure.

12. A vulcanizate of claim 11 wherein said 10 synthetic rubber-like material is a rubbery butadiene-styrene copolymer.

13. A vulcanizate of claim 12 wherein said synthetic rubber-like material is a, 71/29 butadiene-styrene elastomer.

14. A product of vulcanization of 100 parts by weight of a butadiene-styrene rubbery copolymer which has been vulcanized with sulfur in the presence of from 1 to 50 parts by weight of a total residual by-product oil freed from all components boiling below 300 F. as measured at atmospheric pressure and formed during the dehydrogenation of n-butane at a temperature within the range of 1000-1200 F. to produce butenes in the presence of a catalyst consisting essentially of a major proportion of alumina and a minor proportion of chromia.

15. A product of vulcanization of 100 parts by weight of a 71/29 butadiene-styrene copolymer vulcanized with sulfur in the presence of from 1 to 50 parts by weight of a total residual oil byproduct freed from all components boiling below 300 F. at atmospheric pressure and formed during the catalytic dehydrogenation of n-butane in the presence of a catalyst consisting essentially of per cent alumina and 20 per cent chromia, at a temperature within the limits of 1000 and 1200 F. while employing a, space velocity of fromA 300 to 1000 standard gas volumes of n-butane per volume of said catalyst per hour.

16. As a new composition 100 parts by weight of a sulfur vulcanizable synthetic rubber-like material having a raw Mooney viscosity of from 40 to 90 (ML-4) incorporated with from 2 to 10 parts by weight of a total residual by-product oil freed from al1 components boiling below 300 F. at atmospheric pressure and formed during the catalytic dehydrogenation of a C4 hydrocarbon to produce a less saturated C4 hydrocarbon at a temperature within the range of 1000- 1300o F.

17. As a new composition 100 parts by weight of a sulfur vulcanizable synthetic rubber-like material having a raw Mooney viscosity of at least incorporated with from 15 to 50 parts by weight of a total residual by-product oil freed from all components boiling below 300 F. at atmospheric pressure and formed during the catalytic dehydrogenation of a C4 hydrocarbon at a temperature within the range of 1000-1300 F. to produce a less saturated C4 hydrocarbon.

WILLIAM T. COOPER.

No references cited. 

1. A METHOD FOR INCREASING THE PLASTICITY OF A RUBBERY SULFUR-VULCANIZABLE ORGANIC PLASTIC SUBSTANCE CONTAINING UNSATURATED CARBON-TO-CARBON BONDS, COMPRISING INCORPORATING WITH 100 PARTS BY WEIGHT OF SUCH AN ORGANIC PLASTIC SUBSTANCE FROM 1 TO 50 PARTS BY WEIGHT OF A TOTAL RESIDUAL OIL BY-PRODUCT OF CATALYTIC DEHYDROGENATION OF A C4 HYDROCARBON AT A TEMPERATURE WITHIN THE RANGE OF 1000-1300* F. TO PRODUCE AT LESS SATURATED C4 HYDROCARBON, SAID TOTAL OIL BEING FREED OF ALL COMPONENTS BOILING BELOW 300* F. AS MEASURED AT ATMOSPHERIC PRESSURE. 